BSCI202 Lex 2 Exam Practice Exam Version 1

1. The arteries are the vessels that: A. Transport blood away from the heart; B. Transport oxygen-rich blood; C. Transport oxygen-poor blood; D. Transport blood towards the heart; E. Transport blood through the systemic circulation.

A. Transport blood away from the heart. Arteries carry blood away from the heart, regardless of oxygen content.

2. When alveoli are inflated during inspiration, they will: A. Increase the surface area of gas exchange; B. Decrease the resistance in the alveolus; C. Decrease the respiratory membrane thickness; D. Increase the gradient pressure between the alveolus and the capillary; E. All proposed statements occur.

A. Increase the surface area of gas exchange. This is the clearest correct physiological effect; the wording of the other options makes E questionable.

3. When blood passes the mitral valve, it is going from the: A. Right atrium to right ventricle; B. Left atrium to left ventricle; C. Right ventricle to pulmonary trunk; D. Right ventricle to aorta; E. Left ventricle to aorta.

B. Left atrium to left ventricle.

4. The atria contract during: A. First heart sound; B. Second heart sound; C. QRS complex; D. P wave; E. ST segment.

D. P wave. The P wave represents atrial depolarization, which precedes atrial contraction.

5. Ventricular pressure rises above atrial pressure at what point in the cardiac cycle? A. During atrial systole; B. At the end of atrial systole; C. At the beginning of ventricular systole; D. After aortic and pulmonic valves open; E. This does not occur during a normal cardiac cycle.

C. At the beginning of ventricular systole. The rising ventricular pressure closes the AV valves.

6. Which reaction is MOST likely to take place at the pulmonary capillaries? A. HbH + O2 → HbO2 + H+; B. CO2 + H2O → H+ + HCO3−; C. Hb + CO2 → HbCO2; D. Hb + H+ → HbH; E. HbO2 → Hb + O2.

A. HbH + O2 → HbO2 + H+. Oxygen binds hemoglobin in the lungs, promoting oxygen loading.

7. Of the three factors that contribute to resistance to airflow through a tube, which plays the largest role in changing resistance in the human respiratory system? A. Tube length; B. Air viscosity; C. Air humidity; D. Tube diameter; E. Air composition.

D. Tube diameter. Small changes in airway radius greatly change resistance.

8. Which factor would most likely lead to a decrease in peripheral resistance? A. Increased blood viscosity; B. Vasodilation; C. Increased blood vessel length; D. Increased sympathetic stimulation; E. Increased blood volume.

B. Vasodilation. Increasing vessel radius lowers resistance.

9. Arterioles have: A. The largest tunica media-to-vessel-wall ratio; B. The thickest tunica intima; C. The largest lumen; D. The strongest tunica externa with greatest recoil; E. Smooth muscle mostly innervated by the parasympathetic nervous system.

A. The largest tunica media-to-vessel-wall ratio. Their smooth muscle regulates vessel diameter and resistance.

10. In the lungs, pulmonary capillaries are likely: A. Sinusoidal; B. Fenestrated; C. Highly innervated; D. Muscular; E. Continuous.

E. Continuous. Continuous capillaries form the thin exchange surfaces of the lungs.

11. What is the main purpose of the nasal cavity? A. Produce mucus for the lungs; B. Warm, moisten, and filter incoming air; C. Facilitate swallowing; D. Generate sound for speech; E. Regulate blood pressure.

B. Warm, moisten, and filter incoming air.

12. True or false: When a person inflates their lungs, the pressure in the alveoli decreases.

A. True. During inspiration, alveolar pressure falls slightly below atmospheric pressure, allowing air to enter.

13. True or false: Cardiac muscle fibers use aerobic and anaerobic respiration to the same extent to produce ATP.

B. False. Cardiac muscle relies predominantly on aerobic metabolism.

14. True or false: If all nerves to the heart were severed, the heart would instantly stop beating.

B. False. The heart's intrinsic conduction system can generate impulses independently of external nerves.

15. True or false: An increase in afterload decreases stroke volume.

A. True. Greater afterload makes ventricular ejection more difficult.

16. True or false: The lungs contain more terminal bronchioles than respiratory bronchioles.

A. True. Terminal bronchioles are numerous conducting-zone airways before the respiratory zone.

17. True or false: Most CO2 transported by the blood is in the form of dissolved gas.

B. False. Most CO2 is transported as bicarbonate ions (HCO3−).

18. True or false: The pulmonary artery carries oxygen-poor blood to the lungs.

A. True.

19. True or false: Semilunar valves are attached to the myocardium via chordae tendineae and papillary muscles.

B. False. Chordae tendineae and papillary muscles support the AV valves, not the semilunar valves.

20. Veins return blood to the heart against what? A. Gravity force; B. Arterial suction; C. Lower arterial pressure; D. High atrial pressure; E. High ventricular pressure.

A. Gravity force. Venous return from the lower body must overcome gravity.

21. Veins return blood to the heart using what structures located in the vessels? A. Smooth muscles; B. One-way valves; C. Pumps; D. Semilunar valves; E. Activated valves.

B. One-way valves. These prevent backflow.

22. Venous return is aided primarily by contraction of what? A. Intercostal muscles; B. Ventricular contractile fibers; C. Lymph circulation; D. The atria; E. Skeletal muscles.

E. Skeletal muscles. Skeletal muscle contractions compress veins and push blood toward the heart.

23. At rest, after air intake, lung volume reflects a balance between what acting outward? A. Atmospheric pressure; B. Expansion of the chest wall; C. Elastic recoil; D. Arterial blood pressure; E. Alveolar pressure.

B. The expanded chest wall. The chest wall tends to spring outward.

24. At rest, after air intake, lung volume reflects a balance with what acting inward? A. Surfactant volume; B. Surface tension; C. Elastic recoil; D. Alveolar size; E. Dead space.

C. Elastic recoil. The lungs tend to recoil inward; surface tension also contributes to this recoil.

25. At rest, after air intake, alveolar pressure is: A. Higher than atmospheric pressure; B. Equal to atmospheric pressure; C. Lower than atmospheric pressure.

B. Equal to atmospheric pressure. With no airflow, alveolar and atmospheric pressures equilibrate.

26. The secondary bronchi are located in which zone? A. Conducting zone; B. Respiratory zone; C. Residual zone; D. Functional zone; E. Reserve zone.

A. Conducting zone. The secondary bronchi conduct air toward the respiratory regions.

27. The secondary bronchi are surrounded by what? A. Tunica intima; B. Elastic cartilage; C. Skeletal muscle; D. Smooth muscle; E. Hyaline cartilage.

E. Hyaline cartilage. Bronchi contain cartilage plates that support their walls.

28. The secondary bronchi secrete what into the lumen? A. Mucus; B. Lubricant; C. Surfactant.

A. Mucus. Mucus traps particles and helps protect the respiratory tract.

29. PCO2 in blood leaving the systemic capillaries is ___ PCO2 in blood entering the pulmonary capillaries. A. Greater than; B. Lower than; C. Equal to.

C. Equal to. Blood leaving systemic capillaries returns through the veins and enters the pulmonary circulation with essentially the same PCO2 before lung gas exchange.

30. PCO2 in blood entering the pulmonary capillaries is ___ PCO2 in the alveoli. A. Greater than; B. Lower than; C. Equal to.

A. Greater than. CO2 diffuses from blood into the alveoli.

31. PO2 in the alveoli is ___ PO2 in blood leaving the pulmonary capillaries. A. Greater than; B. Lower than; C. Equal to.

C. Equal to, approximately. Oxygen diffuses into pulmonary capillary blood until the partial pressures approach equilibrium.

32. PCO2 in blood entering the systemic capillaries is ___ PCO2 in the tissue cells. A. Greater than; B. Lower than; C. Equal to.

B. Lower than. CO2 diffuses from tissue cells into blood.

33. PCO2 in tissue cells is ___ PCO2 in blood leaving the systemic capillaries. A. Greater than; B. Lower than; C. Equal to.

C. Equal to, approximately. Blood leaving systemic capillaries approaches the PCO2 of the surrounding tissues.

34. PO2 in blood leaving the systemic capillaries is ___ PO2 in blood entering the pulmonary capillaries. A. Greater than; B. Lower than; C. Equal to.

C. Equal to. This is essentially the same deoxygenated venous blood returning to the lungs.

35. Cardiac cycle ordering: What step is “ventricles empty”? A. 1st step; B. 2nd step; C. 3rd step; D. 4th step; E. 5th step; AB. 6th step. Start just after ventricles relax.

AB. 6th step. After ventricular contraction and ejection, the ventricles empty before relaxation begins the next cycle.

36. Cardiac cycle ordering: What step is “semilunar valves open and AV valves close”? A. 1st step; B. 2nd step; C. 3rd step; D. 4th step; E. 5th step; AB. 6th step. Start just after ventricles relax.

E. 5th step. This occurs when ventricular pressure exceeds arterial pressure and ejection begins; note that semilunar valves open after ventricular pressure rises above arterial pressure.

37. Cardiac cycle ordering: What step is “atria contract”? A. 1st step; B. 2nd step; C. 3rd step; D. 4th step; E. 5th step; AB. 6th step. Start just after ventricles relax.

C. 3rd step. Atrial systole completes ventricular filling.

38. Cardiac cycle ordering: What step is “ventricles contract”? A. 1st step; B. 2nd step; C. 3rd step; D. 4th step; E. 5th step; AB. 6th step. Start just after ventricles relax.

D. 4th step. Ventricular systole begins after atrial contraction.

39. Cardiac cycle ordering: What step is “AV valves open and semilunar valves close”? A. 1st step; B. 2nd step; C. 3rd step; D. 4th step; E. 5th step; AB. 6th step. Start just after ventricles relax.

A. 1st step. When ventricular pressure falls below atrial pressure, the AV valves open while the semilunar valves remain closed.

40. Cardiac cycle ordering: What step is “ventricles start filling”? A. 1st step; B. 2nd step; C. 3rd step; D. 4th step; E. 5th step; AB. 6th step. Start just after ventricles relax.

B. 2nd step. Ventricular filling follows opening of the AV valves.

41. Diagram: Label the six parts of the graph showing airflow into the lungs.

Review the original exam diagram. The graph image and its labels were not included in the pasted text, so the six answers cannot be identified reliably from the text alone.

42. Diagram: Label the systemic circulatory system (labels 11–16, including vessels 14 and 15).

Review the original exam diagram. The diagram itself was not included, so the exact labels cannot be determined from the pasted text alone.

43. Open-ended: Explain why the mitral valve is more likely to be replaced than the tricuspid valve, discussing structure, role, and location.

The mitral valve is located between the left atrium and left ventricle and prevents backflow into the left atrium during ventricular systole. It has two cusps supported by chordae tendineae and papillary muscles. Because the left ventricle pumps blood through the high-pressure systemic circulation, the mitral valve experiences greater pressure and mechanical stress than the tricuspid valve on the right side, which pumps blood through the lower-pressure pulmonary circulation. This greater workload may contribute to mitral valve damage and the need for replacement.